1. Field of the Invention
This invention concerns land type seismic exploration, in general, and more particularly concerns a system for locating discontinuities in the seismic cables.
2. Description of the Prior Art
In typical land seismic exploration operations today, the equipment employed uses multiple conductor cables that are extremely long. When they are spread out along the surface of the earth, they will extend for several thousand meters from end to end. The cables which are employed are constructed in sections for portability, and the sections are terminated using electrical connectors. It has been found that during use in the field operations, there are discontinuities in the cables which would develop due to such things as rodents and live stock bites, as well as vandalism and vehicle traffic, in addition to old age of the cables.
Since a seismic field operation involves a number of personnel that are skilled and professional workers, the cost of making seismic surveys is quite high. Consequently, it is important to have the operation continue with dispatch, and to minimize the idle time caused by misfunction such as discontinuities in the cable of the type just mentioned. In the past, it has been necessary for a worker to walk along the cable and carry a radio for communication with the recording station. Then, an intentional short circuit would be made while the circuits were monitored from the recording station, in order to locate the position of a discontinuity.
Consequently, it is an object of this invention to provide a system whereby a short circuiting relay is located at each of the terminal connectors and control is maintained from the recording station, in order to actuate these relays in a predetermined manner for quickly locating any discontinuity.